Shaft-truing devices

ABSTRACT

A manually operated, crankpin truing device, adapted to be mounted on a crankpin without removal of the crankshaft from the engine. Machining of the high surfaces on the crankpin is effected by cutters which are urged, by spring action, to contact such surfaces, but are prevented from making contact with the low surfaces by the cam action between the elliptical pin and the shaft-contacting rollers provided for that purpose.

O United States Patent 1111 @www [72] Inventor Denver L. Walker [56]References Cited 754 Glenside Drive, Lafayette, Calif. 94549 UNITEDSTATES PATENTS [21] A PPL NO- 8633509 9 1,284,106 11/1918 Holton 82/4 B[221 Filed 0*- 27, 119671 1,370,141 3/1921 McNicholas i. 82/4 B [45]Patented Sept f 1,652,868 12/1927 Maloney 82/4 B 2,219,245 10/ 1940Zitzerman 82/4 E Primary Examiner-Leonidas Vlachos Attorney-John WalkerABSTRACT: A manually operated, crankpin truing device, [54] SHAFT'TING,DEFYICES adapted to be mounted on a crankpin without removal of the 7clalms rawmg lgs crankshaft from the engine. Machining of the highsurfaces on [52] U.S. Cl.....- 82/4 B, the crankpin is effected bycutters which are urged, by spring 51/73 action, to contact suchsurfaces, but are prevented from mak- [5 l] Int. Cl B23b 5/18 ingcontact with the low surfaces by the cam action between [50] Field ofSearch 82/4 B; the elliptical pin and the shaftcontacting rollersprovided for that purpose.

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ABY m/ Age/2f SHAFT-TRUING DEVICES This invention relates to crankpintruing devices, and more particularly to a type of tool which can beused on a crankshaft without its removal from an engine. It has beenlong established, that after continued operation the normal wear towhich the crankpins of the crankshaft of an engine are subjected,results in an uneven erosion of material which leaves the crankpins inan out-of-round, or slightly elliptical condition. lf this condition isnot corrected, continued operation of the engine will result in damageto the parts affected.

It is the principal object of the present invention to provide acrankpin truing device which can be applied directly to the crankpinupon the removal of the connecting rod therefrom.

Another objective of the invention is the provision of a device which isautomatically adapted to the removal of material from the high surfacesonly of an out-of-round shaft.

A further object of the invention is the provision of a device which canbe adjusted to resurface a crankpin or shaft to a predetermineddiameter. I

A still further object of the invention is the provision of a devicewhich is simple to manufacture, of compact form and easy to operate.These and other objects of the invention will become apparent during thecourse of the following description, taken in connection with theaccompanying drawing forming a part hereof, and in which:

FIG. I is an elevation of a preferred embodiment of my device.

FIG. 2 is a transverse cross section taken on line 2-2 of FIG. l. FIG. 3is a fragmentary section taken of line 3 3 of FIG. 1.

FIG. 4 is a diagram showing elements ofthe device in a particularangular relationship with reference to an out-of-round shaft.

FIG. 5 is a diagram similar to that of FIG. 4, with the device rotatedthrough an angleof 90.

Referring to the drawing in detail, the body of my device comprises anannular member which has been dimidiated to form tow identical portionsl0, each portion being somewhat less than a complete semicircle. Thematerial removed in the parting of the solid ring leaves a space Ilbetween the halves when they are arranged in their original concentricrelationship. The width of the space l1 will be determined by the rangeof crankpin diameters which a particular tool will be required tohandle.

Adjustable bolts 12 are provided to secure the halves 10 in theiroperating relationship, each bolt passing through a counterboredaperture 13, in one of the sections, and being engaged by a threadedhole 14 in the other section. Compression springs 15, contained in eachof the counterbores of the apertures 13, encircle the bolts, and, beingplaced between the heads of said bolts and the shoulders formed by thebottom of the counterbores, act to resiliently urge the sections ltoward one another. The force exerted by the springs is readilyadjustable by the advancing or retraction of the bolts 12 as desired.The limit to the closing of the halves 10 is governed by the selectedthickness of annular spacers I6, one of which encircles each of thebolts, and is located intermediate the confronting faces 17 at the endsof the halves.

The assembled bolts l2, springs I and spacers 16 are symmetricallyarranged in parallel relationship with a median line passing through thehalves of the body of the tool, said line being nonnal to the dividingspace between the two portions. This line will be referred to thereinaeras the vertical centerline.

FIG. 3 illustrates a detail of a preferred embodiment of a rollerassembly 18 which comprises a double-ended shoulder pin I9, having anantifriction bearing 20 mounted on each end thereof. Each body portion10 is provided with a roller assembly 18. As can be seen by reference toFIG. l, the assemblies are diametrically opposed, are radiallyequidistant and. have their common centerline oriented at 45 to thevertical centerline of the device. A double-counterbored aperture 2l,

located as described above, is provided in each of the portions ll0 forthe reception of the shoulder pins I9, as indicated, the pins beingdriven tightly therein. The counterbore on each side of the portions l0provides a recessed mounting for the bearings 20.

The spacing of the pins 19, and the diameters of the rollers or bearings20 is such that the said rollers project into the circular space 22bounded by the body portions 10 when in their assembled position.

Also extending into the space 22 is a pair of cutters 23. These cuttershave their cutting edges, or surfaces, as the case may be, in adiametrically opposed relationship similar to that of the rollerassemblies 18, their respective center lines being normal to oneanother. The cutters, which extend the length of the tool, are tightlyinserted in slots 24 in the body portions 10 of the device. The radiallocation of the cutting edges, as required by the diameter of aparticular crankpin being operated upon, can be adjusted by the use ofshims 25 of appropriate thickness, as illustrated.

Apertures 2 have been provided in the outer edge of the device, intowhich any suitable implement, such as a rod or bar, may be inserted toeffect rotation. In order to use the device, a crankshaft is rotated toa position where the pin which is to be machined is accessible, andafter removal of the connecting rod, the tool is simply mounted in itsplace, and is then rotated until the operation is complete. Referring toFIGS. 4 and S, it will be noted that the roller assemblies I8 and thecutters 23 are all tangent to a common circle 27 which is equal indiameter to the major axis of a slightly elliptical crankpin P, and fora particular operation, the shims 16 will be of such thickness as toallow all four points of contact to approach a position where they wouldcoincide with the circumference of a circle equal in diameter to theminor axis of the pin. It will be obvious from the fact that as all fourpoints of contact are fixed with reference to their location in theidentically and symmetrically arranged halves of the device, anyvariation of the space 11 will not materially affect this relationship.When the cutters are in contact with the larger surfaces of the pin, asshown on FIG. 4, the springs are free to facilitate the cutting action,as the rollers are held away from contact with the pin. As the tool isrotated into the position shown on FIG. S, the rollers will come intocontact with the larger part of the pin and, by the resulting camaction, will prevent undesirable contact between the cutters and thesmaller part of the pin.

As the operation proceeds, continued rotation of the tool will result inthe high spots being removed until both the rollers and the cutters aremaking contact simultaneously. At his point, the crankpin will beperfectly round and further removal of material will be prevented by theselection and use of spacers 16 of correct thickness.

The foregoing specification describes a preferred embodiment of thetool, wherein ball bearings have been utilized as rollers, in order tofacilitate ease of operation, it should be obvious, however, that otherforms of rollers, or even projecting, nonrotating elements could be usedto perform the function of the illustrated and described means. Also thecutters as shown may be replaced by abrasive elements or hones, andfurther modifications may be made within the spirit and intent of Title35 United States Code, Section l I2, Par. 3.

lclaim:

l. A shaft-truing device comprising a pair of substantiallyr equiformbody members adapted to form a shaft-encircling tool provided withshaft-contacting means and materialremoving means, wherein theimprovement comprises, resilient body connecting means, diametricallyopposed shaftcontacting means and diametrically opposedmaterial-removing means, the diametrical axes of said shaft-contactingmeans and said material removing means being substantially normal to oneanother and the combination of said axes being substantially symmetricalwith reference to a common median line through said body members.

2. A device as in claim I wherein said body-connecting means comprisesspring-loaded bolts.

3. A device as in claim 1 wherein said shaft-contacting means comprisesrotatably mounted elements.

4. A device as in claim l wherein said material removal `means comprisescutting elements.

S. A device as in claim l wherein said material removal means comprisesabrasive elements.

6. A device as in claim l wherein said body members are

1. A shaft-truing device comprising a pair of substantially equiform body members adapted to form a shaft-encircling tool provided with shaft-contacting means and material-removing means, wherein the improvement comprises, resilient body connecting means, diametrically opposed shaft-contacting means and diametrically opposed material-removing means, the diametrical axes of said shaft-contacting means and said material removing means being substantially normal to one another and the combination of said axes being substantially symmetrical with reference to a common median line through said body members.
 2. A device as in claim 1 wherein said body-connecting means comprises spring-loaded bolts.
 3. A device as in claim 1 wherein said shaft-contacting means comprises rotatably mounted elements.
 4. A device as in claim 1 wherein said material removal means comprises cutting elements.
 5. A device as in claim 1 wherein said material removal means comprises abrasive elements.
 6. A device as in claim 1 wherein said body members are provided with means adapted to limit their degree of approach to a predetermined point.
 7. A device as in claim 6 wherein said limiting means comprises annular members encircling said body-connecting means, and being located intermediate the individual body members of said pair. 